Examples with StatementPattern org.eclipse.rdf4j.query.algebra.StatementPattern used on opensource projects

Example 11 with StatementPattern

use of org.eclipse.rdf4j.query.algebra.StatementPattern in project rdf4j by eclipse.

the class ConstructorBuilder method getConstructVars.

/**
 * Gets the set of variables that are relevant for the constructor. This method accumulates all subject,
 * predicate and object variables from the supplied statement patterns, but ignores any context variables.
 */
private Set<Var> getConstructVars(Collection<StatementPattern> statementPatterns) {
    Set<Var> vars = new LinkedHashSet<Var>(statementPatterns.size() * 2);
    for (StatementPattern sp : statementPatterns) {
        vars.add(sp.getSubjectVar());
        vars.add(sp.getPredicateVar());
        vars.add(sp.getObjectVar());
    }
    return vars;
}

Example 12 with StatementPattern

use of org.eclipse.rdf4j.query.algebra.StatementPattern in project rdf4j by eclipse.

the class ConstructorBuilder method buildConstructor.

private TupleExpr buildConstructor(TupleExpr bodyExpr, TupleExpr constructExpr, boolean explicitConstructor, boolean distinct, boolean reduced) {
    TupleExpr result = bodyExpr;
    // Retrieve all StatementPattern's from the construct expression
    List<StatementPattern> statementPatterns = StatementPatternCollector.process(constructExpr);
    Set<Var> constructVars = getConstructVars(statementPatterns);
    // Finally, the spo-bindings are again filtered for duplicates.
    if (distinct || reduced) {
        // Create projection that removes all bindings that are not used in the
        // constructor
        ProjectionElemList projElemList = new ProjectionElemList();
        for (Var var : constructVars) {
            // the distinct
            if (!var.isAnonymous() && !var.hasValue()) {
                projElemList.addElement(new ProjectionElem(var.getName()));
            }
        }
        result = new Projection(result, projElemList);
        // Filter the duplicates from these projected bindings
        if (distinct) {
            result = new Distinct(result);
        } else {
            result = new Reduced(result);
        }
    }
    // Create BNodeGenerator's for all anonymous variables
    Map<Var, ExtensionElem> extElemMap = new HashMap<Var, ExtensionElem>();
    for (Var var : constructVars) {
        if (var.isAnonymous() && !extElemMap.containsKey(var)) {
            ValueExpr valueExpr = null;
            if (var.hasValue()) {
                valueExpr = new ValueConstant(var.getValue());
            } else if (explicitConstructor) {
                // only generate bnodes in case of an explicit constructor
                valueExpr = new BNodeGenerator();
            }
            if (valueExpr != null) {
                extElemMap.put(var, new ExtensionElem(valueExpr, var.getName()));
            }
        }
    }
    if (!extElemMap.isEmpty()) {
        result = new Extension(result, extElemMap.values());
    }
    // Create a Projection for each StatementPattern in the constructor
    List<ProjectionElemList> projections = new ArrayList<ProjectionElemList>();
    for (StatementPattern sp : statementPatterns) {
        ProjectionElemList projElemList = new ProjectionElemList();
        projElemList.addElement(new ProjectionElem(sp.getSubjectVar().getName(), "subject"));
        projElemList.addElement(new ProjectionElem(sp.getPredicateVar().getName(), "predicate"));
        projElemList.addElement(new ProjectionElem(sp.getObjectVar().getName(), "object"));
        projections.add(projElemList);
    }
    if (projections.size() == 1) {
        result = new Projection(result, projections.get(0));
    // Note: no need to apply the second duplicate elimination step if
    // there's just one projection
    } else if (projections.size() > 1) {
        result = new MultiProjection(result, projections);
        if (distinct) {
            // Add another distinct to filter duplicate statements
            result = new Distinct(result);
        } else if (reduced) {
            result = new Reduced(result);
        }
    } else {
        // Empty constructor
        result = new EmptySet();
    }
    return result;
}

Example 13 with StatementPattern

use of org.eclipse.rdf4j.query.algebra.StatementPattern in project rdf4j by eclipse.

the class SPARQLParserTest method testSES1922PathSequenceWithValueConstant.

@Test
public void testSES1922PathSequenceWithValueConstant() throws Exception {
    StringBuilder qb = new StringBuilder();
    qb.append("ASK {?A (<foo:bar>)/<foo:foo> <foo:objValue>} ");
    ParsedQuery q = parser.parseQuery(qb.toString(), null);
    TupleExpr te = q.getTupleExpr();
    assertNotNull(te);
    assertTrue(te instanceof Slice);
    Slice s = (Slice) te;
    assertTrue(s.getArg() instanceof Join);
    Join j = (Join) s.getArg();
    assertTrue(j.getLeftArg() instanceof StatementPattern);
    assertTrue(j.getRightArg() instanceof StatementPattern);
    StatementPattern leftArg = (StatementPattern) j.getLeftArg();
    StatementPattern rightArg = (StatementPattern) j.getRightArg();
    assertTrue(leftArg.getObjectVar().equals(rightArg.getSubjectVar()));
    assertEquals(leftArg.getObjectVar().getName(), rightArg.getSubjectVar().getName());
}

Example 14 with StatementPattern

use of org.eclipse.rdf4j.query.algebra.StatementPattern in project rdf4j by eclipse.

the class SPARQLParserTest method testSES1927UnequalLiteralValueConstants1.

@Test
public void testSES1927UnequalLiteralValueConstants1() throws Exception {
    StringBuilder qb = new StringBuilder();
    qb.append("ASK {?a <foo:bar> \"test\". ?a <foo:foo> \"test\"@en .} ");
    ParsedQuery q = parser.parseQuery(qb.toString(), null);
    TupleExpr te = q.getTupleExpr();
    assertNotNull(te);
    assertTrue(te instanceof Slice);
    Slice s = (Slice) te;
    assertTrue(s.getArg() instanceof Join);
    Join j = (Join) s.getArg();
    assertTrue(j.getLeftArg() instanceof StatementPattern);
    assertTrue(j.getRightArg() instanceof StatementPattern);
    StatementPattern leftArg = (StatementPattern) j.getLeftArg();
    StatementPattern rightArg = (StatementPattern) j.getRightArg();
    assertFalse(leftArg.getObjectVar().equals(rightArg.getObjectVar()));
    assertNotEquals(leftArg.getObjectVar().getName(), rightArg.getObjectVar().getName());
}

Example 15 with StatementPattern

use of org.eclipse.rdf4j.query.algebra.StatementPattern in project rdf4j by eclipse.

the class ConstructorBuilder method buildConstructor.

private TupleExpr buildConstructor(TupleExpr bodyExpr, TupleExpr constructExpr, boolean explicitConstructor, boolean distinct, boolean reduced) {
    TupleExpr result = bodyExpr;
    // Retrieve all StatementPattern's from the construct expression
    List<StatementPattern> statementPatterns = StatementPatternCollector.process(constructExpr);
    Set<Var> constructVars = getConstructVars(statementPatterns);
    // Finally, the spo-bindings are again filtered for duplicates.
    if (distinct || reduced) {
        // Create projection that removes all bindings that are not used in the
        // constructor
        ProjectionElemList projElemList = new ProjectionElemList();
        for (Var var : constructVars) {
            // the distinct
            if (!var.isAnonymous() && !var.hasValue()) {
                projElemList.addElement(new ProjectionElem(var.getName()));
            }
        }
        result = new Projection(result, projElemList);
        // Filter the duplicates from these projected bindings
        if (distinct) {
            result = new Distinct(result);
        } else {
            result = new Reduced(result);
        }
    }
    // Create BNodeGenerator's for all anonymous variables
    Map<Var, ExtensionElem> extElemMap = new HashMap<Var, ExtensionElem>();
    for (Var var : constructVars) {
        if (var.isAnonymous() && !extElemMap.containsKey(var)) {
            ValueExpr valueExpr = null;
            if (var.hasValue()) {
                valueExpr = new ValueConstant(var.getValue());
            } else if (explicitConstructor) {
                // only generate bnodes in case of an explicit constructor
                valueExpr = new BNodeGenerator();
            }
            if (valueExpr != null) {
                extElemMap.put(var, new ExtensionElem(valueExpr, var.getName()));
            }
        }
    }
    if (!extElemMap.isEmpty()) {
        result = new Extension(result, extElemMap.values());
    }
    // Create a Projection for each StatementPattern in the constructor
    List<ProjectionElemList> projections = new ArrayList<ProjectionElemList>();
    for (StatementPattern sp : statementPatterns) {
        ProjectionElemList projElemList = new ProjectionElemList();
        projElemList.addElement(new ProjectionElem(sp.getSubjectVar().getName(), "subject"));
        projElemList.addElement(new ProjectionElem(sp.getPredicateVar().getName(), "predicate"));
        projElemList.addElement(new ProjectionElem(sp.getObjectVar().getName(), "object"));
        projections.add(projElemList);
    }
    if (projections.size() == 1) {
        result = new Projection(result, projections.get(0));
    // Note: no need to apply the second duplicate elimination step if
    // there's just one projection
    } else if (projections.size() > 1) {
        result = new MultiProjection(result, projections);
        if (distinct) {
            // Add another distinct to filter duplicate statements
            result = new Distinct(result);
        } else if (reduced) {
            result = new Reduced(result);
        }
    } else {
        // Empty constructor
        result = new EmptySet();
    }
    return result;
}